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Re: [i386] Question about Constraint Modifier character in smaxdf3 pattern.
- From: Richard Guenther <richard dot guenther at gmail dot com>
- To: "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>
- Cc: "Kumar, Venkataramanan" <Venkataramanan dot Kumar at amd dot com>
- Date: Mon, 20 Feb 2012 12:27:51 +0100
- Subject: Re: [i386] Question about Constraint Modifier character in smaxdf3 pattern.
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- References: <7794A52CE4D579448B959EED7DD0A4721A9122@sausexdag04.amd.com> <alpine.DEB.2.02.1202191642160.6275@laptop-mg.saclay.inria.fr>
On Sun, Feb 19, 2012 at 4:43 PM, Marc Glisse <marc.glisse@inria.fr> wrote:
> On Sun, 19 Feb 2012, Kumar, Venkataramanan wrote:
>
>> Sphinx3 benchmark segmented when built and ran with -Ofast and
>> -fprefecth-loop-arrays.
>
> [...]
>
>> In my case the register 367 is sNAN.
>
>
> -Ofast implies -ffast-math which implies -ffinite-math-only:
> ? ?Allow optimizations for floating-point arithmetic that assume that
> ? ?arguments and results are not NaNs or +-Infs.
>
> so I am not sure what you expect exactly.
Irrespective of -ffast-math the .md file looks ok - the tree and RTL level
mark their min/max as commutative, so if there is an error the error is
that sminmax is used, not that the pattern for it has its operand marked
as commutative (this may mean that without -fno-signed-zeros and
-ffinite-math-only [s]minmax cannot be used on x86).
Richard.
> --
> Marc Glisse